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Abstract Background The effect of different thawing procedures for ram semen frozen in minitubes and mini straws on the fertility of sheep was tested in a field trial. Methods Altogether, 719 Norwegian Crossbred ewes, aged between six months and six-and-a-half years from 8 farms, were inseminated vaginally in natural oestrus with frozen-thawed semen. Minitubes were thawed at 70°C for 8 sec (T70) and mini straws either at 50°C for 9 sec (S50) or at 35°C for 12 sec (S35). Results Vaginal insemination with 200 × 106 spermatozoa resulted in 25-days non-return rates of 63.2, 59.6, and 62.5% (overall 61.8%), respectively, and lambing rates of 56.8, 55.0, and 59.2% (overall 57.0%), respectively. No significant effect on fertility (as 25-days non-return- or lambing rate) was seen for straw type/thawing temperature (P = 0.5/0.5), but semen filled in mini straws and thawed at 35°C resulted numerically in the highest lambing rate (59.2%). A significant effect was, however, seen for farmer (P = >0.0001/>0.0001) and ram (P = 0.009/0.002). Moreover, age of the ewes had a significant effect on the NR rate (0.007), but not on lambing rate (P = 0.2). Conclusion A vaginal deposition of frozen ram semen containing approximately 200 × 106 spermatozoa, filled in mini straws and thawed at 35°C is a simplified technique that under field conditions and used on a do-it-yourself regime gives acceptable lambing rates in Norway.

Abstract Background The four casein proteins in goat milk are encoded by four closely linked casein loci (CSN1S1, CSN2, CSN1S2 and CSN3) within 250 kb on caprine chromosome 6. A deletion in exon 12 of CSN1S1, so far reported only in Norwegian goats, has been found at high frequency (0.73). Such a high frequency is difficult to explain because the national breeding goal selects against the variant's effect. Methods In this study, 575 goats were genotyped for 38 Single Nucleotide Polymorphisms (SNP) located within the four casein genes. Milk production records of these goats were obtained from the Norwegian Dairy Goat Control. Test-day mixed models with additive and dominance fixed effects of single SNP were fitted in a model including polygenic effects. Results Significant additive effects of single SNP within CSN1S1 and CSN3 were found for fat % and protein %, milk yield and milk taste. The allele with the deletion showed additive and dominance effects on protein % and fat %, and overdominance effects on milk quantity (kg) and lactose %. At its current frequency, the observed dominance (overdominance) effects of the deletion allele reduced its substitution effect (and additive genetic variance available for selection) in the population substantially. Conclusions The selection pressure of conventional breeding on the allele with the deletion is limited due to the observed dominance (overdominance) effects. Inclusion of molecular information in the national breeding scheme will reduce the frequency of this deletion in the population.

A survey was conducted between April and July 2007 to generate information on dry season feeding management and livestock poisoning in the southern rangelands of Ethiopia. A total of 119 pastoralists were interviewed using a semi-structured questionnaire. Moreover, additional information was obtained through informal discussions. The study revealed that pastoralists have rich knowledge of natural resource management and utilization and employ various strategies such as migration, collection of grasses and pods, and cutting branches to overcome feed scarcity during dry/drought periods. Migration of livestock and people to areas with better grazing is the widely used strategy. However, the implementation of this strategy is diminishing as a result of changes such as bush encroachment, expansion of settlements, and crop cultivation in dry-season grazing lands. The respondents also indicated the presence of poisonous plants in the rangeland, and about 20 such plants were identified by the respondents. Various species and classes of livestock are reported to be affected by toxic plants particularly in the dry and early rainy seasons when feed is in short supply. A more extensive survey is required to document all poisonous plants in the rangelands and to identify the major toxic principles in the different species. Future development interventions should consider the prevailing constraints and potentials of the rangelands with active participation of the pastoralists.

In two field trials (T1 and T2), the effect of two different extenders for buck semen was tested. Semen from six (T1) and seven (T2) bucks of the Norwegian Dairy Goat breed was diluted either in a milk-based extender containing egg yolk (M) or in a commercially available extender without egg yolk [Andromed(®) (A)]. Dilution in M was performed in a two-step procedure including centrifugation of the ejaculates and removal of the supernatant, while dilution in A was performed in one step. During the two trials (T1 and T2) 514 and 714, does, respectively, were artificially inseminated during natural oestrus, and the farmers performed the inseminations themselves after attending an artificial insemination (AI) training course. Vaginal insemination with 200 × 10(6) spermatozoa diluted in M resulted in a 25-day non-return rate (NRR) and kidding rate of 37.3% and 24.5%, respectively, while semen diluted in A resulted in 31.7% NRR and a kidding rate of 19.8% (T1). In T2, NRR and kidding rate for AI performed with semen diluted with M were 42.7% and 28.5%, respectively, while dilution in A gave 37.2% NRR and a kidding rate of 26.8%. There was no significant effect of extender in the two trials [T1:p=0.068 (NRR), p=0.148 (kidding rate), T2:p=0.096 (NRR), p=0.38 (kidding rate)], but farmer had a significant effect on the fertility parameters in both trials. In conclusion, the present studies may indicate that Andromed(®) is suitable for buck semen. However, more research is necessary to confirm the results and to improve the fertility of does after vaginal AI with frozen-thawed semen., (© 2010 Blackwell Verlag GmbH.)

In a field trial, 633 ewes from 24 farms were inseminated vaginally using liquid semen (150 x 10(6) per dose) collected from 15 rams. The semen was either diluted with a milk-based extender (M), filled in 0.2 ml straws and stored for 12 or 24 h (M12, M24) or diluted with M but with the addition of gelatine, filled in 0.5 ml straws and stored for 12 or 24 h (G12, G24). The hypothesis was that a larger volume and the addition of gelatine would prolong the survival of the spermatozoa. The ewes, aged between 6 months and 5.5 years, were allocated into four groups and inseminated after natural oestrus by the farmers themselves with a dose of 150 x 10(6) spermatozoa. Inseminations in the groups (M12, M24, G12, G24) resulted in lambing rates of 69.6%, 63.6%, 69.4% and 58.3% (overall 65.2%), respectively. Farmer (p < .0002) had a significant effect on the lambing rate, while ram, age of the ewe and dilution rate/addition of gelatine/storage time had not. A pair-wise comparison of the lambing rates between the four groups showed that significant lower results were only achieved for G24 compared with M12. None of the other comparisons showed significant differences. In conclusion, a higher dilution rate of the AI-dose together with the addition of gelatine to the semen extender did not lead to improved fertility results after storage for 24 h when compared with standard AI-doses used in Norway.

Background: Since the dawn of genetics, additive and dominant gene action in diploids have been defined by comparison of heterozygote and homozygote phenotypes. However, these definitions provide little insight into the underlying intralocus allelic functional dependency and thus cannot serve directly as a mediator between genetics theory and regulatory biology, a link that is sorely needed., Methodology/principal Findings: We provide such a link by distinguishing between positive, negative and zero allele interaction at the genotype level. First, these distinctions disclose that a biallelic locus can display 18 qualitatively different allele interaction sign motifs (triplets of +, - and 0). Second, we show that for a single locus, Mendelian dominance is not related to heterozygote allele interaction alone, but is actually a function of the degrees of allele interaction in all the three genotypes. Third, we demonstrate how the allele interaction in each genotype is directly quantifiable in gene regulatory models, and that there is a unique, one-to-one correspondence between the sign of autoregulatory feedback loops and the sign of the allele interactions., Conclusion/significance: The concept of allele interaction refines single locus genetics substantially, and it provides a direct link between classical models of gene action and gene regulatory biology. Together with available empirical data, our results indicate that allele interaction can be exploited experimentally to identify and explain intricate intra- and inter-locus feedback relationships in eukaryotes.

Rhode Island Red (RIR) and Fayoumi chickens were evaluated on-station in a college farm and on-farm in village farms, whereas local chickens were only tested under on-farm condition. Traits recorded are egg production and egg quality, body weight and feed efficiency at 4, 8 and 12 months of age. Significant age effect was found for most traits except for shell thickness, albumen height and egg length. Also, significant breed by management system interactions were found for all traits measured in both systems. Fayoumi chickens were higher in egg production in both management systems. Moreover, they were higher than RIR in feed efficiency. RIR were higher in most egg quality traits and had higher weight gain. Local chickens performed below the two exotic breeds in most of the traits, but had higher weight gain than Fayoumi. Chickens kept on-farm had poorer performance than those kept on-station in all traits except for yolk colour.

A field trial was performed in order to evaluate the effect on fertility of different straw types, freezing protocols (one- or two-step) and thawing procedures (35 degrees C and 70 degrees C) using frozen-thawed ram semen. A total of 791 Norwegian Crossbred ewes were artificially inseminated during natural oestrus with semen collected from nine mature and proven Norwegian Crossbred rams. A milk-based extender was used for dilution. The ewes were allocated into one of the following three groups based on the different straw types and thawing temperatures: medium straw (0.5 ml) thawed at 35 degrees C for 20 s (Med35), medium straw thawed at 70 degrees C for 8 s (Med70) and mini straw (0.25 ml) thawed at 35 degrees C for 15 s (Mini35). The semen to be frozen in mini straws was re-concentrated by centrifugation. Sperm number in each insemination dose was approximately 200 x 10(6) spermatozoa. The fertility results [as 25-day non-return rate (NRR)] for Med35, Med70 and Mini35 were 53.1%, 50.8% and 58.3%, respectively, and the lambing rates 49.8%, 46.8% and 53.8%, respectively. No significant main effects were seen for straw type/thawing temperature (p = 0.17), ram (p = 0.06) or age of the ewe (p = 0.18) on NRR or lambing rates (p = 0.19, p = 0.16 and p = 0.27, respectively). Both NRR and lambing rate differed significantly among farms (p < 0.0001).

The aim of this paper was to characterize the diversity among haplotypes based on 22 single nucleotide polymorphisms (SNPs) and one deletion within four casein genes in two geographically distant goat populations, the Sicilian Girgentana breed and the Norwegian goat breed. Forty Girgentana goats were genotyped for the aforementioned polymorphisms and the resulting data set was compared with 436 goats from the Norwegian population previously genotyped for these markers. Several casein gene polymorphisms were not in Hardy-Weinberg equilibrium either in Girgentana, or in the Norwegian breed. The SNP haplotype frequencies for the four casein genes were calculated and despite the large geographical distance and phenotypic divergence between these breeds, a proportion of casein loci haplotypes were found to be identical between both Norwegian and Girgentana goats. However, for the CSN2 gene there were no common haplotypes between the two populations. The level of linkage disequilibrium between the casein genes was less in the Girgentana population than in the Norwegian population.

Genotype x environment interaction (G x E) effects on live weaning weights of lambs were studied by using the 2 breeds Norwegian White sheep (NWS; heavy, long-tailed) and Spel sheep (Spel; lighter, short-tailed) as genetic groups (G). A total of 37,338 NWS lambs and 30,075 Spel lambs born from 1989 to 1999 on 40 farms that kept both breeds together were included in the analyses. Environment was characterized by farm x year (E). In a mixed linear model framework, significance of the random G x E effect and breed-specific environmental variances were tested by using a log-likelihood approach. Directions and magnitudes of the effect were described through variance component estimates. An across-genotype environmental correlation was also used. There was a significant G x E effect on lamb BW; significant breed differences were found for variance of flock x year effects, indicating different phenotypic plasticities with changing flock x year environments, with the NWS being more sensitive to environmental change. Further, the breed-specific residual variance was greater for NWS, indicating that the effects of environmental variation were larger for the weaning weights of the NWS breed within flock and year. Further, the correlation between flock x year effects for the 2 breeds was significantly different from unity (0.82 +/- 0.02), indicating that the common environment is "perceived" differently in the 2 breeds. The best environment for one breed is not necessarily best for the other breed, and vice versa. Solutions of flock x year effects may be used to describe how environmental characteristics such as climate and topography affect the production of different genotypes, and for clustering of environments, thus facilitating improvement of breeding programs and management schemes for domestic and wild ungulate populations.

In goat milk the most abundant proteins are the casein genes, CSN1S1, CSN2, CSN1S2, and CSN3. Mutations have been identified within these genes affecting the level of gene expression, and effects on milk production traits have been reported. The aim of this study was to detect polymorphisms (SNPs) in the casein genes of Norwegian goats, resolve haplotype structures within the loci, and assess the effect of these haplotypes on milk production traits. Four hundred thirty-six Norwegian bucks were genotyped for 39 polymorphic sites across the four loci. The numbers of unique haplotypes present in each locus were 10, 6, 4, and 8 for CSN1S1, CSN2, CSN1S2, and CSN3, respectively. The effects of the CSN1S1 haplotypes on protein percentage and fat kilograms were significant, as were the effects of CSN3 haplotypes on fat percentage and protein percentage. A deletion in exon 12 of CSN1S1, unique to the Norwegian goat population, explained the effects of CSN1S1 haplotypes on fat kilograms, but not protein percentage. Investigation of linkage disequilibrium between all possible pairs of SNPs revealed higher levels of linkage disequilbrium for SNP pairs within casein loci than for SNP pairs between casein loci, likely reflecting low levels of intragenic recombination. Further, there was evidence for a site of preferential recombination between CSN2 and CSN1S2. The value of the haplotypes for haplotype-assisted selection (HAS) is discussed.

The effect of vaginal and cervical deposition of frozen-thawed semen on the fertility of sheep was tested in a field trial in which 543 Norwegian crossbred ewes aged between six months and five-and-a-half years from 10 farms were inseminated after natural oestrus. Cervical insemination with 200 x 10(6) spermatozoa resulted in 25-day non-return and lambing rates of 75.4 and 72.7 per cent, respectively, and vaginal insemination gave rates of 71.3 and 67.4 per cent; the cervical inseminations produced significantly higher lambing rates (P=0.04). There were significant differences between the lambing rates for different rams (P=0.006) and different farmers (P=0.003), and there was a significant interaction between farmer and deposition site (P=0.03). After vaginal insemination fertility was encouragingly high, but the results varied with the farmer, and different flock and management conditions.

The effect of vaginal and cervical deposition of liquid semen stored at room temperature on the fertility of goats was tested in a field trial in which 217 Norwegian Dairy goats aged between 6 months and 7.5 years from 14 farms were inseminated after natural oestrous. Cervical insemination with 200 x 10(6) spermatozoa resulted in 25-day non-return and kidding rates of 87.0 and 78.0%, and vaginal insemination gave 85.5 and 74.3%, respectively. There was no significant difference between the cervical and vaginal inseminations (P = 0.59 for the 25-day non-return and P = 0.40 for the kidding rates). Farm had a significant effect on the 25-day non-return rate (P = 0.03) but not on the kidding rate (P = 0.07). There were no significant differences between the fertility rates for different bucks (P = 0.36 for the 25-day non-return and P = 0.15 for the kidding rates). Fertility results after vaginal insemination were encouragingly high. Vaginal insemination is a simple, less costly and time consuming technique compared to others, also bringing into focus the animal welfare aspects of the artificial insemination procedure. As the final goal is to establish a technique that could be applied similarly on a large scale by all farmers, vaginal insemination must be considered as a method that would simplify the use of liquid buck semen in Norway.

The effect of different thawing procedures for ram semen frozen in minitubes and mini straws on the fertility of sheep was tested in a field trial in which 727 Norwegian crossbred ewes, aged between six months and five-and-a-half years from nine farms, were inseminated with frozen-thawed semen in natural estrous. Minitubes were thawed at 70 degrees C for 8 s (T70) and mini straws either at 70 degrees C for 5 s (S70), 50 degrees C for 9 s (S50), or 35 degrees C for 12 s (S35). Cervical insemination with 200 x 10(6) spermatozoa resulted in 25-day non-return rates of 78.7, 69.0, 73.6, and 72.9% (overall 73.6%), respectively, and lambing rates of 77.6, 66.1, 71.4, and 68.9% (overall 71.0%), respectively. There was a significantly higher lambing rate for T70 compared to S35 (P=0.03) and S70 (P=0.02), respectively, but not compared to S50 (P=0.29). Age of the ewes (P=0.02), farmers (P=0.02) and the interaction between farmer x straw type/thawing temperature (P=0.01) had a significant effect on the lambing rate. In conclusion, the superior fertility results achieved for minitubes compared to mini straws have to be carefully evaluated in relation to the possible application of a more rational semen production and simplified semen handling at AI, when using mini straws thawed at 35 degrees C.

We studied the influence of two different extenders, a milk-based versus a TRIS-based extender, using a split-sample technique, on fertility after single and double vaginal inseminations in natural estrous in Norwegian Crossbred ewes. Semen from 21 Norwegian Crossbred rams, all aged approximately 0.5 years, was used for AI of totally 561 Norwegian Crossbred ewes housed at 37 different farms. The farmers performed the inseminations themselves. The ewes were allocated to four parallel groups based on the two extenders and single or double inseminations (2 x 2). The farmers were recommended to inseminate the ewes between 12 and 24 h after detection of natural standing estrous. Vaginal insemination with cooled liquid semen diluted in the milk-based extender resulted in a statistically significant (P<0.01) better fertility of about 10% units both as 25-day NR (non return rate)-and lambing rates, compared with semen diluted in the TRIS-based extender. Double inseminations gave significantly higher (P=0.03) fertility results for both extenders expressed as 25-day NR results, but was not quite statistically significant when expressed as lambing rates (P=0.06) compared with single insemination. The overall 25-day NR results for the milk-based extender (66.4%) after single inseminations is in accordance with both the national results (67.1%) based on vaginal inseminations of 11,377 ewes, as well as with the results from a previous study in the same region achieving a 25-day NR results of 63.3%. In conclusion, liquid ram semen diluted in a milk-based extender and vaginally inseminated once in natural heat, with a semen dose of 150 x 10(6) spermatozoa, gave acceptable fertility results and is to be recommended as the method of choice in Norway.

The effect of the deposition site and the numbers of sperm on the fertility of sheep was tested in a field trial in which 1292 Norwegian crossbred ewes aged between six months and five-and-a-half years from 52 farms were inseminated with liquid semen after natural oestrus. Cervical insemination with 150 x 10(6) and 75 x 10(6) spermatozoa resulted in 25-day non-return rates of 63.7 and 56.1 per cent, and vaginal insemination gave non-return rates of 63.3 and 56.6 per cent, respectively. There was no significant difference between the cervical and vaginal inseminations, but the inseminations with 150 x 10(6) spermatozoa gave significantly higher non-return rates (P=0.004). There were significant differences between the non-return rates for different rams (P<0.0001) and farmers (P=0.0002) but the age of the ewe had no significant effect.

Differential leukocyte (WBC) counts in blood from clinically healthy silver foxes (n=32) and blue foxes (n=37) obtained from an automated hematology analyzer (Technicon H*1 Hematology System) with canine software were compared with microscopic differential WBC counts (M-diff). There was good agreement between the automated differential cell count (A-diff) and the M-diff for neutrophil and lymphocyte percentages. The correlation was lower for monocyte percentages and variable for eosinophil percentages. There was no significant difference between the A-diff and M-diff in either fox species. The A-diff counts were very precise, and may be a good alternative to the traditional M-diff for screening populations of clinically healthy foxes or for studies on stress and animal welfare. Intercept values, however, indicated a constant bias that must be taken into account before interpreting results based on different methods of analysis

When selecting in a finite population of honeybees there is a conflict between gain in a quantitative trait and increasing homozygosity, and therefore the frequency of inviable diploid drones. The consequences when using different mating, import, and selection strategies on diploid drone frequency and genetic gain, was explored with Monte Carlo computer simulations.Within a closed population breeding structure, mass selection gave the highest genetic gain in the quantitative trait, but also the largest increase in percentage diploid drones and queens with unacceptably-low brood viability. Mass selection combined with truncation selection against queens having more than 15% diploid drones gave a comparable genetic gain and was the best strategy of the ones studied to avoid diploid drones. Within-family selection (one replacement per sib group) gave the least genetic gain, and a frequency of diploid drones comparable to random (no) selection. It was intermediate between mass selection and mass selection combined with viability selection concerning the frequency of diploid drones.Insemination with pooled and homogenized semen originating from all breeder queens (30), as compared to natural mating with 12 randomly-selected drones, had little effect on the genetic gain and on the overall frequency of diploid drones (10 to 15% by generation 20).The effect of opening the closed breeding population for the import of external queens every generation, by exchanging breeder queens of lowest performance with a corresponding number of new queens (5, 10and 15 out of 30), was also investigated. Under mass selection (natural mating as well as artificial insemination) the frequency of diploid drones and the proportion of queens discarded were reduced because of low brood viability. However, artificial insemination was superior to natural mating considering the latter criterion. If the imported queens were at the same genetic level for the quantitative trait under selection as the whole breeding population at that generation, or 10% better, the genetic gain was respectively slightly reduced and approximately maintained. If the imported queens were of inferior quality (equal to the initial population) the import of queens slowed genetic progress considerably.